-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=63501&p=106353#p106353

--+------------------------------------------------------------------+
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--+------------------------------------------------------------------+
--|                                      Developed by : Mario Jemic  |
--|                                          mario.jemic@gmail.com   |
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--+------------------------------------------------------------------+

function Init()
    indicator:name("Half Trend Overlay");
    indicator:description("");
    indicator:requiredSource(core.Bar);
    indicator:type(core.Indicator);

	
	indicator.parameters:addGroup("MACD Calculation");
	 indicator.parameters:addInteger("Amplitude", "Amplitude", "", 2, 2, 5000);
 
 
	
	indicator.parameters:addGroup("Style");
	indicator.parameters:addColor("Up", "Up color", "", core.rgb(0, 255, 0));
	indicator.parameters:addColor("Down", "Down color", "", core.rgb(255, 0, 0));
	indicator.parameters:addColor("Neutral", "Neutral color", "", core.rgb(0, 0, 255));
	
   
end

-- Indicator instance initialization routine
-- Processes indicator parameters and creates output streams
-- TODO: Refine the first period calculation for each of the output streams.
-- TODO: Calculate all constants, create instances all subsequent indicators and load all required libraries
-- Parameters block

local Up,Down, Neutral;
local first;
local source = nil;
 

local  open=nil;
local  close=nil;
local  high=nil;
local  low=nil;

local Amplitude;
local Indicator;
 


function Prepare()

    Up = instance.parameters.Up;
    Down= instance.parameters.Down;
    Neutral= instance.parameters.Neutral;   
    Amplitude = instance.parameters.Amplitude;
	source = instance.source; 
	
	assert(core.indicators:findIndicator("HALFTREND") ~= nil, "Please, download and install HALFTREND.LUA indicator");
	Indicator=core.indicators:create("HALFTREND",  source , Amplitude, Up, Down);
	    
   
    local name = profile:id() .. "(" .. source:name() .. ", " .. source:barSize()..", ".. Amplitude
	 
	..  ")";
    instance:name(name);
	if (nameOnly) then
        return;
    end
	
	first= Indicator.DATA:first();

    	
	open = instance:addStream("openup", core.Line, name, "", core.rgb(0, 0, 0), first);
    high = instance:addStream("highup", core.Line, name, "", core.rgb(0, 0, 0), first);
    low = instance:addStream("lowup", core.Line, name, "", core.rgb(0, 0, 0), first);
    close = instance:addStream("closeup", core.Line, name, "", core.rgb(0, 0, 0), first);
    instance:createCandleGroup("OVERLAY", "OVERLAY", open, high, low, close);
		
end

-- Indicator calculation routine
function Update(period, mode)
	
    open[period] = source.open[period];
	close[period] = source.close[period];
	high[period] = source.high[period];
	low[period] = source.low[period];
	
			if period < first then
			open:setColor(period, Neutral);	
			return;
			end
	

   
	
			   Indicator:update(mode); 
		open:setColor(period,Indicator.DATA:colorI(period));	   
 end